The letter must explain who is gifting the money, where the donor's funds are coming from and the relationship between the donor and the recipient. It states how much you're getting and from whom.If borrowers plan to use gift money, they must request a gift letter from their lenders. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment. See What is backup withholding, later. By signing the filled-out form, you: 1. Affidavit of Motor Vehicle Gift Transfer. A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. A gift letter is a piece of legal, written correspondence explicitly stating that money received isn't expected to be repaid.